Electrical vibrator unit



2 Sheets-Sheet l Em' meander E. c. GUEDON ET AL ELECTRICAL VIBRATOR UNIT Filed Feb. 28, 1954 Dec. s, 1936.

Patented Dec. 8, 1936 UNITED STATES PATENT OFFICE ELECTRICAL VIBRATCR UNIT Application February 2s, 1934, serial No. 713,324

26 Claims.

The present invention relates to radio power supply systems, and more particularly to vibratory-contact, circuit-controlling means for use in connection with a direct-current transformer or inverter systemfor supplying anode and other operating-potentials'to radio apparatus.l Preferably such a system may be of the` type disclosed in a co-pending application of Frederic Shoup and Alexander D. Burt, Serial No. 689,720, filed September 16, 1933, and assigned to the same assignee as this' application. x

As shown inthe `application above referred to, a circuit controlling device of the vibratory contact type, in connection with a suitable` transformer, may be utilized instead of batteries for the supply of operating potentials to automobile radio receiving apparatus and the like, vwhereby all the power for such apparatus may be obtained from the single low voltage source provided by the automobile storage battery.

A form of vibrator device of the character under consideration, for use in connectionwlltth a transformer, may' include a pair of primary contacts, a pair4 of secondary contacts, and an electric vibrator as motor means for alternately connecting said contacts for eachwinding with the respective input and output circuits of the system. Additional operating contacts for the vibrator motor means may also be provided.

vibratory contact circuit-controllingV devices of the type above described may be constructed within relatively small dimensions advantageously for use in portable and automotive radio apparatus and the like. However, .the vibratory contact o'r armature elements thereof may be subjected to various degrees of vibrationas well asv other adverse vconditions of operation incidental to automotive and portable use.

Interference with the normal smooth vibratory action of the armature or moving element may ordinarily ailect the amplitudean'd Acontinuity of the voltage output'from a power supply system involving a vibratory contact circuit controlling .device suiliciently to interfere with the quiet voperation of the radio apparatus associated thereovercome while retaining desirable features of f an improved vibrator7notor-actuated switching mechanism for alternately establishing and breaking a plurality of circuits in a direct current transforming system.

Another object of the invention is to provide, in a system of the above character, including-a transformer having a divided winding, an improved means for establishing a circuit alternately through one part and then through a remaining part of the winding.

Another object of the invention is to provide an improved electro-magnetically actuated device for alternately making and breaking a circuit, said device including an armature arranged for movement within the iield of an electro-magnet, between or along, but out of contact with the poles of said electro-magnet.

A further object of the invention is to provide an improved circuit making and breaking device ln a radio power supply system which embodies vibratory circuit making and breaking'means, including a swinging armature or reed, arranged formovement along, but never in contact with, an active pole face of an actuating electro-magnet, and an energizing winding for the electromagnet which includes a shunt circuit closed to decrease the energization of said electro-magnet below an effective point when the circuit is closed.

A further object of the present invention is to provide a vibratory contact or inverter device which, while being completely electrically and mechanically shielded, to prevent sound and electrical radiation, may readily and quickly be opened for inspection and adjustment.

It is a still further object of the present invention to provide an improved circuit controlling means of the vibratory contact type for power supply for radio apparatus and the like, which is adapted to be mounted in and form part of said apparatus, and which is electrically and mechanically shielded therein as a unit. i

In a present preferred embodiment of the invention, a vibratory circuit controlling device is provided with a flexibly mounted vibrator unit on a relatively heavy base; 'I'he base forms part of a sound and electrical shielding container for the vibrator unit and associatedl electrical circuit elements. The amature element of the vibrator unit is arranged to standvertically and to lie in a plane transverse of the base and common to the direction of travel and major movement of a vehicle, whereby motion of the armature is at a right angle to said plane, and the operation of the armature is thereby substantially unaffected. by the spring action and the acceleration or deceleration of the vehicle.

To complete the sound and electrical shielding, the heavy base is arranged to receive a'plurality of nested or concentric, spaced shield cans on screw threaded shoulders which serve simultaneously as mounting and spacing means therefor. This construction provides a dead air space between the shield cans for sound insulation and provides effective electrical shielding for the apparatus contained therein.

The device is adapted to be mounted in an opening in the shielding of a receiver or other apparatus and to be connected with a transformer element, hereinafter referred to, within the apparatus shielding. 'I'he vibrator unit includes contact and motor means arranged forY smooth operation and easy adjustment with a maximum degree pf compactness. i

Further, in accordance` with the invention, the unit itself, the armature and certain of the contact elements of the vibrator motor means are arranged to have predetermined periods of vibration. The armature is also arranged to move between the poles of an actuating electro-magnet close to, but out of contact with, the adjacent faces of said poles, whereby the armature is prevented from striking the poles, thereby obtaining smoother and quieter operation.

The invention will, however, be better understood from the following description when considered in connection with the accompanying drawings, and its scope will be pointed out in the appended claims.

In the drawings, Fig. 1 is a view in perspective and substantially full size, of a vibratorrectifier device embodying the invention, and with shield covers removed for inspection;

Fig. 2 is a cross-sectional view of the same, on the same scale and with shield covers in place;

Fig. 3 is a sectional view, and on the same scale, of a portion of the apparatus shown in Figs. 1 and 2, taken on the line 3-3 of Fig. 2;

Fig. 4 is a further sectional view, and on the same scale, of the portion of the apparatus shown in Fig. 3, taken on the line 4 4;

Fig. 5 is a circuit diagram of the apparatus of Fig. l to 4 inclusive, in connection with a power supply circuit and transformer therefor;

Figs. 6, '1, and 8 are front, side and top views respectively, and substantially lfull size, of a vibrator device embodying a modification of the invention, Fig. 8 being partly in section taken on the line 8-8 of Fig. 7; I

Fig. 9 is a front view partly in section, of ,a further modification similar to the device shown in Figs. 6, '7, and 8, but on a reduced scale, and in connection with a schematic diagram of a.A power supply circuit including a transformer with which it operates; and

Fig. 10 is a side view, partly in section, of a detail modification of a portion of the devicev of Figs. 1, 2, 3 and 4.

Referring to Figs. 1 to 4, inclusive, Il is a relatively heavymetallic base member, preferably. cylindrical in form, and provided with shoulders or stepped concentric threaded portions II and I2 on which are mounted correspondingly threaded concentric nested metallic and are so arranged-that a relatively wide air space I5 is provided between them in which may be placed sound absorbing lining material such as felt, as indicated at I6. 'I'he interior of the innermost shield'can may also be lined with a' similar material, as indicated at I1, thereby improving the sound absorbing qualities of the inner walls of the container.

The shield cans are preferably formed of thin sheet metal, in one piece, with threaded open ends as shown, and the base member is preferably a relatively heavy die-casting, relatively thick in cross section, as indicated more clearLv in Fig. 2, to aid in preventing the ton of sound vibrations from the interior of the oontainer.

In the present example, the base member is formed with a hollow interior and the bottom is arranged to depend from the main body of the base member, as indicated at Il, to provide a.

cup or interior4 central well in which may be located electrical circuit elements, such as a pair of circuit controlling condensers Il-II.

Electrical leads indicated at 2l, for the interior electrical apparatus are arranged to pass through the well and out from the base at the bottom to provide shielded electrical connections with external electrical apparatus hereinafter described.

To this end, the base is adapted to be mounted on and form part of the shielding of an electrical apparatus, and in the present example, is arranged to extend through an opening 2l in the apparatus shielding indicated at 22, and to be mounted on said shielding through the medium of suitably spaced ears 23, as shown in Pigs. 1 and 2. The base member serves to close the opening 2| by extending through it to the interior thereof, and to complete the shielding, while at the same time it is easily removable therefrom.

The leads, electrical condensers, or other devices within the base are secured in place by filling the well with insulating compound indicated at 24. It will also be seen that the compound serves to seal the lead openings against sound leakage. Suitable electrical connections with the apparatus or circuit elements in the base are made before pouring the compound, and it will be seen that the base, apparatus, and leads may be built as one unit in the vcourse of manufacture, the con- .nection leads extending above and below the base,

-as shown more clearly in Fig. 2.

The container provides an electrically shielded and sound-proof housing for the vibrator unit 25, per se, which is flexibly mounted therein in spaced relation to the base member, as shown more fully in Fig. 2. The vibrator unit is also preferably slightly spaced from the walls of the container so that it may move independently of and relative to the base member on a flexible mounting and spacing means.

The flexible mounting and spacing means for the vibrator unit is provided preferably by an annular flexible or resilient connecting memberor mounting sleeve 26, located between the base 21 of the unit and the shield base at I0,.and engaging at its opposite ends an annular groove 28 in the unit base and a similar groove 29 in the shield base. The walls of the sleeve are thickened to provide annular inner flanges or beads 30 to fill the grooves and to `provide a secure connection' therewith as shown more clearly in Fig. 2.

The walls of the-sleeve 26 are of suflicient thickness and stiffness to hold the vibrator unit base normally parallel with and raised above the shield base. The sleeve is of such length that the vibrator unit base is sufficiently spaced from the shield base to provide a flexible connection with the base and a length of connecting leads sufficient to provide flexibility without imparting stiffness to or breakage of the leads.

It will be noted that the walls of the tubular sleeve are tapered so that the walls lie at an angle to the vertical whereby vertical forces of vibra'- tion incidental to the operation ofthe device are absorbed or prevented vfrom reaching the base by the walls of the sleeve in bending rather than by being compressed. The mounting sleeve is preferably of flexible rubber for this purpose, of sufficient stiffness, normally to support the vibrator unit without being deformed.

The vibrator unit further comprises an armature body or mass 3| movable on a pair ofv spaced supporting springs or reeds 32 between the spaced pole pieces 33 of an electro-magnet provided by a magnet winding 35 on a core 36 to which the pole pieces ar-e secured.

The pole pieces 33 are fiat rectangular platesarranged in parallel relation to each other on opposite ends of the core and winding to provide spaced substantially parallel pole faces 31 in opposing relation to each other.

The armature is supported for movement between or along, but out of contact with, the pole pieces of the electro-magnet on the free ends of the flexible mounting springs or reeds 32. The opposite ends of the lsprings 32 are secured to a mounting pedestal or central post 38 integral with the base 21. The mounting pedestal or post is also provided, at the top, with a bracket 39 on which the electro-magnet is mounted by means of suitable threaded studs 40 passing therethrough from the pole pieces.

The base 21, the pedestal 38, and the bracket 39 are preferably of insulating material, whereby the Ivarious pieces of apparatus attached thereto and spaced, may be operated at differing electrical potentials. To protect the bracket 39 from breakage when the rpole pieces are clamped down too tightly,-a separator plate, preferably of brass, is inserted between the pole pieces and the bracket as indicated at 4I.

The' armature mounting springs straddle the pedestal 38 on opposite sides and are secured to the pedestal and base on suitable side lugs 42 by means of clamping screws 43. The springs are provided with electrical terminal lugs 44 to which electrical connection is made with the leads 20 as indicated.'

It will be noted that the mounting springs 32 are flat adjacent to the fixed ends and that they are provided with curled or flanged edges 32a more adjacent to the armature whereby the rethe armature mass.

gion of bending of the springs is confined to the fixed ends of the springs and at a. distance from This' permits the armature to operate more uniformly about substantially a fixed pivot on a relatively long radius arm.

The mounting springs are given an initial set or bend, adjacent to the fixed ends to place them under tension, thereby to apply a biasing force to the armature in a direction away from the pole pieces. tracted position away from the pole pieces, as shown in Figs. 1, 3 and 4, it engages the free end of a. short Vspring contact member 45 which is clamped or secured at ythe opposite end to the mounting pedestal 38, as` indicated by the clamping plate 46 and clamping bolts 46a-through the pedestal. The free end carries a contact 41 cooperating 'with a contact 48 on the armature 3|.

The contacts '41 and 48 provide the make-andbreak means for the electro-magnet 45 for operating the armature 3|` as a vibrator motor means.,

The circuit connection for the electro-magnet is completed through one of the mounting springs 32 for the armature, thence through the armature and the contacts 41 and 48, thence through the contact spring 45, bolts 46a, terminals 50, a magnet lead 49, the electro-magnet winding 35, and a second lead 49a, back to the source of supply (not shown). This connection is indicated most effectively` in Figs, 2 and 3.

It will be noted particularly in Fig. 2, that a resistor element l is connected to the lug 50 and one of the terminal lugs 44 for the armature mounting spring 32, thereby placing the resistor in parallel with the operating contacts 41.

and 48 for the electro-magnet. Being located in direct connection with the contacts, the resistor may be supported directly4 by its connection therecontact 41 and open the electro-magnet circuit.

The electro-magnet is then de-energized and the armature is permitted to return under the biasing action of the mounting springs 32 to again close the contacts 41 and 48.

It has been found desirable that the fixed contact member 45 be sufficiently flexible to follow the armature a short distance when attracted by the electro-magnet, to permit the contacts 41 and 48 to remain closed over an appreciable portion of the forward movement of the armature, and it has further been found to be desirable that the contact 45 be stiffness controlled; that is, have a natural frequency of vibration higher than that of the armature in order that it may follow accurately and without chatter, the movement of the armature as above pointed out.

To that end, in the vibrator motor means, as shown and described, the armature mass or body is mounted on supporting spring means providing a relatively long radius of vibration, and the make-and-break contact means is provided with a relatively short spring contact leaf or member 45.

1tw111 be noted m Fig. 3, particularly, manne 75 spring contact member 45 is provided with a stop means adjacent to its free or contact end, in the form of an adjustable stop screw 52, threaded at an angle through the pedestal 33 in alignment with said free end of the contact member. A suitable lock nut 53 is provided by which the screw is held in adjustment.

The adjustment is such that the contact member 45 is stopped against the end of the stop screw 52 when the amature 3l has traveled inwardly toward the pole pieces a predetermined distance such that its inertia or momentum will carry it the'remaining distance of its travel. The stop screw serves to cause the contacts 41 and 45 to open abruptly at said predetermined point. It has been found that by placing the stop screw at an angle-to the plane of the contact member or spring 45, as shown, and for meeting the contact member adjacent to the tree end thereof, whipping of said member is prevented.

With this arrangement, having a predetermined mass, the armature may be given a uniform vibratory motion. 'By proper adjustment of the stop means 52 the excursions of the armature on opposite sides of a central position may be made substantially equal and uniform, as is desirable for circuit controlling devices of this character. It thus provides an effective means for reciprocating a common contact between other spaced contacts for uniform circuit controlling purposes, such as' smooth full wave rectification.

In the present example, the armature is, in addition to the contact member 45, caused to meet one or more buffer or spring contact members at either end of its travel or excursion from a central position. The arrangement is such that it is normally held at one end of its travel by the tension or biasing action of the supporting spring leaves 32, being shown in this position in Figs. 1, 3 and 4. It is moved to the opposite end of its travel by inertia and the impulse from the electro-magnet, under control of the contact member 45 and the stop means 52, through opening and closing of the contacts 41 and 45 at the proper points in its travel.

In the present example, two pairs of buffer springs or spring contact members 54 are provided on opposite sides of the armature in opposing relation to each other and on opposite sides of the pedestal 38.- The buiIer springs or spring contact members are secured at the lower ends by suitable clamping bolts 55 which pass through the pedestal as shown more clearly in Fig. 3. The bolts serve to clamp a pair of opposing springs, and are provided with suitable insulating washers 56 to prevent electrical connection between the pair of springs clamped by the common means.

The spring contact members are substantially parallel with each other and with the spring contact member 45 and the spaced supporting spring leaves 42, standing vertically with respect to the base 21 and being substantially the same length as the supporting springs 32 for the armature mass.

The spring contact members are bent or deformed in the *direction of. the armature and against the stop fingers, being thereby normally under tension and urged or biased into engagement with stop ngers.

The upper or free ends of the spring contact members are arranged to meet the armature in the region of the limits of its excursions to resiliently stop it. When relieved from contact with the armature the springs are met and stopped by projecting stop means or fingers 51 provided on the upper end of and integral with the mounting pedestal or post 35. It will be noted that the stop means in connection with the vibrator contact member 45 is provided by the adjustable stop screw or stud 52.

Electrical switching contacts are also provided between the armature and the buffer springs, comprising the contacts 58, 59, 50 and 6i, and the contacts 52 cooperating therewith and carried by the armature. The arrangement is such that the armature provides an intermediate common contact movable between pairs of spaced spring contacts or contact'elements, for controlling separate circuits hereinafter described.

The intermediate common contact 'provided by the armature, operates to complete each circuit alternately by engagingvflrst with one and then with the other of the two opposing contacts, such as the contacts 55 and 59, or the contacts 50 and 5i. 'I'his is shown more clearly in Fig. 4.

In order that the contacts may be arranged in balanced relation to each other on the armature, the body or mass of the latter is provided by two plates 53 suitably secured together, back to back. by suitable means such as rivets 54, which also secure the supporting springs 32 thereto. The contacts 52 are individually riveted to each plate in order that said contacts may be aligned coaxially in pairs, back to back, as shown in Fig. 4. The contacts are thereby all arranged in opposing balanced relation to each other on opposite sides oi the armature and on opposite sides of the make-and-break contact 48.

Sufilcient force is imparted to the armature by the supporting springs 32 to raise the buffer or contact springs from the stop iingers slightly as the armature is caused to travel away from the electro-magnet in one direction and to the normal rest position shown in the drawings, whereby the contacts 58 and'll are iirmly closed with the armature contact 62 in the ,interval during which the buer springs are out of contact with the stop fingers.

As the armature moves toward the ends of its excursions, that is, towards the spring contact members or buffer springs, such members, being free for movement against the tension of the spring elements, are moved outwardly from the stop fingers when engaged by the armature. Firm closure of the contacts over an extended period is thereby effected, such period ending abruptly with sharp contact break when the spring contact members meet the stop fingers on the return movement.

'I'he outer contact members or buffer springs are normally under tension urging said elements into engagement with the stop lingers 51. The latter are rigid and interconnected, being integral with the pedestal or center post 38. The center post or pedestal, with the stop fingers, provides a rigid intermediate member between the buffer springs or spring contact members. The stop means or fingers provide movement limiting means underlying each contact member or element and serve to meet the contact members abruptly on the return movement of the armature therefrom, and thus aid in eecting the sharp break for the contacts above mentioned.

'Ihe mass of the armature serves to provide sufficient inertia further to aid in eiecting positive closing of the contacts over an appreciable interval of time after the bufi'er springs 54 leave the stop fingers 51 at each end of the armature i aooasrr Y Y orexcursion. Stating the abovein other after the contactsclose, the energy stored armature' causes it to continue to move -the stiffness of the buffer springs I4 until it is' gradually brought to rest, the contactsv o being in the closed position. The energy thereby` f stored in the buffer springs with slight loss due to damping is reimparted to the amature onthe return movement until the buer springs strike the stop fingers and the contacts reopen. 'The closing and opening of the contacts is repeated at the opposite end of-the amature movement.

It will, therefore, be seen that the buffer being resilient, and functioning somewhat onthe order of bumpers in stopping the movement'of the armature, or as combined re s ilient contact members and buffer or stop means 'for the armature, also exert a force in reversingv the movement-ofthe armature and thus aid in obtaining smooth vibratory action of the armature. The frequency of vibrationfof thearmature': -in the present example -is about `'I cycles per fseeond. A higher frequency may however vbe provided if desirable or necessary.

It will be noted that the amature kis normally in a retracted position away fromthe velectro-magnet pole pieces and in this position.

' biasing force of the electro-magnet con-tact spring 4l is added to that of the buersprings 54.

'lhls added biasing force is balanced in the arrangement shown, by the opposing stiffness in' the supporting springs 32 which, as has hereinbefore been stated, are deformed or set to provide a biasing force in the opposite direction and toward the contact spring 45. f Y

Y'With this arrangement the mass of thev armature is free to vibrate between the buffer springs and the contacts carried thereby, substantially uniformly on either side of the mid-position,

which may be considered as that in which the armature,as the center contact element, is substantially mid-way betwen the outer contacts.

fReferring now to yFig. 5, the vibrator rectifier .device ofthe preceding figures is shown schematically in a circuit diagram for a power supply system, and for the purpose of better understanding the invention, like parts shown in the diagram bear the same reference numerals as in the preceding figures.

'Ihe actuating electro-magnet is indicated at Ilfin connection with an armature representing the armature and supporting spring construction of the preceding figures. The arma- 5'5* is provided with contacts 62-62 and with a pair of cooperating contacts 58 and 59` and the second pair of cooperating contacts 80 and 6I. E The electro-ma`gnet operating contacts are indicated at 41 and 4I.

v'.llhse base member of the vibrator rectifier is indicated at I0, and the shield` containers are indicated hy the enclosure in the dotted outlines IlV and i4. The base I0 is grounded, as indicated at. The pair of circuit controlling condensers isare located inside the base I0, as is also the shunt resistor 5I. The latter is connected with .c the armature and with the contact 41, as shown,

`indicated at I1, is provided in connection with :the vibrator contact device to be controlledwhereby it is `connected in shunt to the vibrator or'electro-magnet operating contacts 41 and 4l. I n the present power supply system and as hereinbefore referred to, a step-up transformer,

thereby. The ltransformer is provided with a 'divided primary winding 6l and a divided Seqtap 14 and the secondary having a center-tap 1|.

'The transformer isrlocated between a low Wolt- `age batterysouree of current indicated by input supply leads 1! and higher voltage output supply leem 13 for anode and`grid circuits and the like, ofradio and electronic tube apparatm (not shown).

y In the presentv example, the vibrator device is arranged vto connectthe input low voltage cir- 'euit lor leads 12-ilrst across one half and then acrosstheotherhalfofthe primary ofthey transformer l1. While the secondary is similarly e alternately.. connected lwith the lhigh voltage outlput circuit. or leads 1I.

`For'this purpose the armature-8l is connected. ,y

asindicated, by the lead 14 to`ground through .connection with the casing or base member IVI,

while; the primary terminals are connected molan mais indicated at u, wim the primary vcontact membersiil'and ll. The secondary tert minals-are also similarly connected through leads v indicated, at 1I with the secondary contact members Il and 5I.- `The circuit controlling condensers i9' are connected each between one of the secondary-contacts Il and 59 and theground, through a connection as shown, between the lead 14andtheleads16.

. The low voltage input circuit and the high y voltage output circuit are connected together and grounded as indicated at the point 11. With this arrangement the two circuits are interconnected von the low voltage or grounded side, which in the present example is indicated as the negative side of each circuit. `v f v Operating current for the electro-magnet 8B is taken through a supply lead 18 from the 'posi-l tive side of the low voltage input circuit 12, `and after passing through'the contacts 41 and 4l is returned to the negative side of the said circuit at 11 through the armature, the lead 14 and the base member I I.

With this arrangement the electro-magnet l5, under control of the contacts 41 and 48, causes the amature. l5 to vibrate uniformly between the contacts and Il 'and the contacts 59 and l sulting in the secondary are rectiiied and applied as a-pulsating 'direct current to the output circuit 13. For the purpose of ltering the output current a condenser 18 is connected preferably adjacent to the terminal 1l of the secondary, across the output circuit.

- 'I'he ratio'of the transformer is such that the low supply voltage at the input circuit 12, which inan automobile radio supply circuit may be of the orderof 6-8 volts, is stepped up and appliedr to the output circuit 13 at a.l value suitable for use with'radi'o tube circuits such as the anode or 10 output circuits, and for this 'Purpose may be of the order of 270 volts.y

Referring now to the modication shown in Figs. li, 'l and 8, a vibrator unit is shown in which a central core member for an actuating elecn' tro-magnet 86 provides a supporting member for the unit. The electro-magnet winding 86 is located in spaced relation to the ends 81 of the core member, which are formed to be gripped and held in resilient mounting means hereinafter described in connection with the embodiment shown in Fig. 9. The core is preferably cylindrical, as shown, and the ends 81 are of reduced diameter to provide shoulders 08 for preventing longitudinal movement of the core when mounted for use in a vibrator device.

The coreis also provided at one end with an extended pole piece 89 having an active pole face 90 with which is associated a vibratory armature or reed 9| having its free end in close spaced relation to the pole face 90, and having a flexible mounting means at the opposite end for holding it rigidly against movement in all directions except that for vibratory movement past the pole face 90.

In the present example, the armature or reed 9| is mounted on a supporting bar 92 extending transversely of the core 88 at the opposite end thereof, substantially parallel with the pole piece 89. The armature or reed 9| is flexibly secured to the supporting bar 92 through the medium of a flat strip 93 of spring material. The strip is sufficiently stiff, however, and is bent or tensioned slightly in a direction to hold the armature in a slightly retracted position eccentric with respect to the center of magnetic force existing at the pole face 90. This position is shown clearly in Fig. 6. l

By providing the supporting bar 92 and spring member 93, as well as the armature pole piece and magnet core, of magnetic material, it will be seen that the construction above described provides substantially a closed magnetic circuit having a single air gap 94 which is relatively narrow. It will also be noted that the pole piece 89 is provided with an elongated pole face extending along and in the same direction as the armature body to present a relatively large -iux diffusing area to the armature.

At the opposite ends of the electro-magnet winding and between the pole piece 89 at one end and the supporting bar 92 for the armature at the opposite end, are spaced washers or supporting plates 95 and 96; of insulating material, preferably substantially rectangular in form. The ends of the plates, as indicated at 91 and 98, surround the armature and form spaced supporting and insulating means for the current carrying and other elements of the vibrator.

In the present example, the armature is grounded to the core. However, it will be appreciated that in case it is desired to provide an insulated armature the strip of resilient spring material 93 may be formed of resilient insulating material.

Furthermore,` the armature, while forming part of the magnetic circuit of the electro-magnet 86, also provides a common contact carrying member or element between two spaced buffer springs or' outer contact carrying elements 99 and |00 for effecting vibratory switching connection with external circuits such as are shown hereinafter.

The buier springs or contact elements are preferably of thin, fiat, current-conducting spring material and are mounted at one end as indicated at on the insulating support or plate 9S, in opposing spaced relationto each other on opposite sides of the armature and substantially in the plane of vibrational movement of the latter.

At their free ends, the buffer or contact springs bridge members `short to effect a switching operation of the armature from one contact to the other.

In the present example, the armature is arranged to close contact with one ot the buffer springs as shown when in a normally de-energid position slightly eccentric to the center of the pole face 90 and the magnetic eld of the electromagnet. In this position the armature contact is closed with the contact |04 and is in slightly spaced relation to the contact |09.

A desired spaced relation of the outer contacts is maintained by stop means carried by, and preferably integral with the upper washer or mounting member 95. The stop means is provided by slotting the mounting member on each side of the armature as indicated at |00, to provide |06 forming stop means or fingers, on opposite sides oi' a central opening |01 for the armature.

With this arrangement, the stop fingers serve to meet the spring contact elements and as the armature moves, cause abrupt separation of the contacts and a corresponding sharp break of circuits which may be controlled by the contacts. The contact and stop ilnger arrangement is shown more clearly in Fig. 8 in which the armature is shown at the extreme end of its travel after having been under the attraction of the electromagnet when energized.

It will be noted that in this position the buffer or contact spring may be lifted away from the stop fingers, while in the de-energized position shown in Fig. 6 the contact or buifer spring |04 may similarly be raised or lifted from its corresponding stop nger means. 'I'his permits the contacts to remain closed over an appreciable period until the contact finger again meets its associated stop finger means. In order that the period of vibration of the armature may be reduced and that the frequency of vibration may be adjusted to a predetermined value the amature may for example be loaded by increasing its mass, preferably at the free end, by suitable means such as a detachable weight |08. In the present example, the stiffness of the armature suspension and buiier springs together with the mass of the armature, is such that the armature is caused to vibrate at a desired frequency.

The armature is caused to vibrate under oontrol of the vibrator contacts which may be separate from the contacts |02, |03 and |04 for switching control. In the present example, one of the vibrator contacts is carried by the armature as indicated at |09 and the other of which is flexibly mounted in cooperative relation thereto as indicated at ||0. The contact |09 is carried by the armature on a shorter radius than the main-contacts and the associated contact III is carried by a spring bracket which lies at one end between the armature and the spring contact member |00, and extends substantially parallel therewith and in spaced relation to both the armature and the spring contact member. The bracket is offset, as shown more clearly in Fig. '1, and is secured to the supporting member 98 in spaced relation to the adjacent spring contact member.

I'he bracket is secured as shown lpreferably on f the outer end 99 of the mountingmember 99.A

The contacts |99 and ||9 vcorrespondv to the contacts 41 and 49 of the embodiment of the invention hereinbefore described, andserve to control the electro-magnet in substantially the same manner, that is, as the amature isattracted by the electro-magnet the contacts |99` and I I9 open at a predetermined point determined by the stop finger ||2 and cause the electromagnet to be de-energized. The armature con` tinues under the momentum imparted-to it by the impulse from the electro-magnet and continues on until the operating contacts are closed in the opposite direction and its force is expended v. in meeting the stiffness of the buffer orcontact spring, whereupon it is returned under the biasing action of its spring mounting and the energy stored in the buier or contact spring, and upon closure of the contacts the cycle vis repeated.

With the arrangement shown, the armatureis free to vibrate without danger of striking the' pole piece, since it swings in a plane substantially paralleling the plane of the pole face andclosely adjacent thereto. The armature is supported for movement along, but never in contact with the pole face.

The flat, flexible spring element 93 provides a resilient mounting device by which the armature is normally held in eccentric position relative to the center of the magnetic field of the pole piece and by which the armature is maintained for reciprocation along said face in close proximity thereto, but out of contact therewith.

Viewed in one of its aspects, the vibrator unit in the present example may be considered to comprise three spaced contact elements` which` ex- 'tend in approximate parallelism in the same direction, being formed of resilient material and supported at one end. Intermediate, or stop members are disposed between the central element and each of the outer elements, which outer elements are normally under a tension urging them into engagement with said stop members.

The stop means or intermediate members are integral with the supporting member or bracket and are, therefore, interconnected. In the present construction they are rigid, being connected rigidly by the supporting member with the core of the electro-magnet. Since the core and the stop fingers are thus interconnected rigidly, the relation of the stop fingers andthe pole piece is xed and predetermined.

'I'he above relation is preferably such that with f o and the'magnetic field, substantially as shown in Fig. 6. The armature thus tends to move into andl out of 'alignment with the pole piece along and adjacent to the pole face andv slightly out of contact therewith to provide a lrelatively narrow airgap.

Referring now to Fig. 9 in which like' parts throughout bear the same reference numerals as in Figs. 6, '1 and 8, the vibrator unit is shown mounted at its ends in resilient blocks H5 of sound and vibration absorbing material such `as ammi o ,7.

Woof; rubbenwmonueedepted tobepreeeeo.

' shielding. l ,1

shown,intoalignedopenings ||9inabasemem j bei' III and the arm'i13 of a pedestalJlIintegral with or carried by the base ||`l.` The vibrator unit is arranged to be supported in a vertical position between the base and the pedestal arm.

Each of the blocks of resilient materialismoand a cooperating open ended shield can |23,

i118 or absorbing material |24, thereby providing with the base member IIT., a closed container for' t the vibrator unit, having sound and electrical The electro-magnet 99 is arranged tofbeinter .mittently energized through the operation of the contacts |92 and |93 whereby separate operf ating contacts therefor are eliminated. In addition, this modification is provided with a nat bar pole piece indicated at |29, bring in a position to attract the armature 9| toward'it to reduce the air gap indicated at |29. "Ihis provides asimplifled pole piece construction, but has the disadvantage that the armature approaches the pole piece. 'Ihe air gap may, however, be adjusted by rbending the pole piece y|29 or in other suitable manner, so that the armature is stopped by the stiffness of the buffer or contact spring 99, without striking the pole piece.

The electro-magnet 99 is provided with terminal leads |21 and |29, which are connected respectively to a terminal |39 for the contact spring 99 and to a terminal |29 for the amature 9|,

as indicated. The-arrangement is such thatthe electro-magnet for voperating the vibrator is connected in parallel with the intermediate common movable contact element, provided by the armature, and an outer contact element toward which the armature is moved in response to ener-A gization of the electro-magnet, whereby thev 'rne vvibrator unit is enclosed by the base u1 which is arranged to surround the base and to seat at'its upper end on the pedestal arm to which it is securedby asuitabie means such as la screw The shield 'can is lined with sound insulat-`l 2liv electro-magnet is shunted out upon establish- Y ment of the circuit controlling contacts. Stated in other words, the vibrator deviceis arranged to include two spaced normally opened circuit controlling contact devices, one of which serves in the movement of the armature to make and break intermittently, a circuit through the electro'magnet,and thereby to cause vibration of the armature. The contacts are connected, therefore, in a circuit which is closed to. de-energize the electro-magnet vwhen the contact device is closed.

The switching arrangementprovided by the vibratory contact device is jointly utilized to control the energization of. a transformer |3|. Fior this purpose the transformer primary, indicated at |92, is' provided with a center tap connection |33 with one side of a power supply circuit |34., while the terminals of the primary winding are CII.

contacts |02 on the armature with the contacts |03 and |04, causes each half of the primary winding |32 to be energized alternately.' This establishes across the terminals |31 of the secondary winding |38 an alternating voltage which is thus derived from any suitable low voltage direct current source (not shown) which may be connected with the supply leads |34.

The voltage established across the terminals at |31 is dependent upon the step-up ratio of the ytransformer and may be utilized in any suitable manner, or may be rectified in accordance with the arrangement shown in the preceding embodiment of the invention by the provision of additional secondary contacts, or by other suitable means.

It will be seen that the electro-magnet energizing circuit is taken through one half of the primary winding, which is the lower half of the Winding as viewed in the drawings. 'I'his arrangement has the advantage of simplifying the apparatus, but since the operating contacts for the vibrator motor means or electro-magnet and the circuit controlling contacts are the same, separate individual adjustment of the two sets of contacts is not possible.

Since this embodiment of the invention is otherwise the same as the embodiment shown in Figs. 6, 7 and 8, further description is not believed to be necessary.

The vibrator device may be arranged for plugin connection with the transformer and other portions of the circuit. For example, the base may be provided with plug-in contacts as terminals for the supply leads, thereby providing for the easy removal and replacement of the device in an electrical apparatus.

A plug-in arrangement is particularly desirable in the case of portable and automotive radio apparatus, where the vibrator unit may require frequent inspection as a result of use under unusual and adverse operating conditions.

It is at present preferred that the base of the unit be provided with plug-in terminals and in Fig. 10, to which attention is now directed, a modification of the base of the device -shown in Figs. 1 to 4 inclusive, is shown as adapted for plug-in connection.

Referring to Fig. 10, the base of the vibrator unit is indicated at |40 and is provided with stepped spaced threaded portions |4| and |42 for receiving screw-threaded shielding means such as is shown in the foregoing figures above referred to. The apparatus well is reduced in width and elongated as indicated at |43, to provide space at the bottom of the base for the insertion of suitably insulated plug-in type of terminal pins |44. The terminal pins may be located on either or both sides of the well as shown in the drawings and project from the base a sufficient distance to readily be gripped by any suitable cooperating contact means (not shown).

The contact pins are preferably insulated from each other and the baseby being mounted in an insulating plate |45 pressed into a suitable recess |46 in the base. It will be noted that the apparatus well |43 is connected with the base through a web above the insulating plate and that the web is provided with openings through which the lead wire connections to the interior apparatus is made. As plug-in connection means for radio tubes and like devices are well known, further description is believed to be unnecessary.

It Will be seen, however, that in each of the embodiments of the invention the vibrator per se is mounted as a unit within a closed substantially soundproof electrically shielded casing providing for resiliently retaining the vibrator unit in substantially a vertical position. It will also be seen that the armature in each embodiment extends in a vertical direction, thereby particularly adapting the device for use in portable electrical and radio apparatus for the reason that the device may be mounted so that the plane of movement o! the armature is transverse of the base and at a right angle to one or both of the directions of movement to which the apparatus is subjected in use. The armature is, therefore, substantially unaffected by motion in the directions above mentioned.

It will further be seen that in each embodiment of the invention, the vibrator device is provided with a relatively heavy base member on which a removable shield and sound proof members are mounted to enclose the vibrator unit. The unit, as disclosed in Figs. 6 to 9, inclusive, has the advantage that it may be mounted by inserting the ends of the core member in resilient mounting blocks in the casing or frame provided therefor.

In the several embodiments of the inventionY the mass of the vibrator unit per se is such that its natural frequency of vibration is lower than that of the armature, whereby vibratory movement of the unit does not appreciably affect the vibratory action of the armature. In the embodiment of Figs. 1 to 4, inclusive, the electromagnet is mounted at one end of the base or pedestal, while the armature supporting spring contact members or reeds are mounted on what may be regarded as the opposite end of the base or the base proper. In each embodiment of the invention, the resilient contact members are mounted to stand vertically and extend substantially parallel with each other with the free ends at the tcp of the device adjacent to the electro-magnet pole piece or pole pieces.

We claim as our invention:

1. A vibratory circuit controlling device comprising in combination a base member, and a vibrator unit resiliently mounted thereon in spaced relation thereto, said unit including an armature mounted to vibrate in a plane substantially at a right angle to and transverse oi the base member, and said unit having a mass and stiffness such that its natural period of vibration is longer than the vibrational period of the armature.

2. A vibratory circuit controlling device comprising in combination a base member,y and a vibrator unit resiliently mounted thereon in spaced relation thereto, said unit including an armature mounted to vibrate in a plane substantially at a right angle to and transverse of the base, and said unit having a mass and stiffness such that its natural period of vibration is longer than the period of vibration of the armature, resilient spring contact members arranged in contacting relation with the armature to meet the latter at the ends of its vibrational movement, one of said members having a length and stiffness such that its natural period of vibration is shorter than that of the armature, whereby in connection with the armature such member is stiffness controlled.

3. A vibratory circuit controlling device comprising in combination a base member, and a vibrator unit resiliently mounted thereon in spaced relation thereto, said unit including an armature mounted to vibrate in a plane substantially perpendicular to and transverse of the base, and said y '9,003,311 Y 'una having a mass and stiffness such that its natural period of vibration is longer than the vibrational period of the armature, and a pair of nested spaced shield cans removably mounted on said base through the mediumof screw-threaded connections therewith and providing with the base shielded enclosure means for the vibrator unit.'

4. An electrical ,vibrator unit comprising a base, an electro-magnet supported from and lying in a plane substantially at a right angle to and intersecting said base, said electro-magnet having a pair of pole pieces providing Vspaced parallel pole faces extending transversely, of the base, a

vibratory armature having a body movable between said pole i'aces but out of contact therewith,

vflexible spring mounting means for said armature secured to the base and having a free end carrying said armature body, a plurality of elongated spring contact members extending substantially parallel with said spring mountingmeans from the base and having free ends arranged in contacting relation to the armature on opposite sides thereof, one of said contact springs being relatively short and having a natural frequency oi' vibration higher than the period oi vibration of the armature, and said vibrator unit having a natural frequency of vibration lower than that of the amature, and means for mounting said device whereby said vibrator unit stands in a vertical position whereby the plane oi vibration of the armature may be oriented to extend in a predetermined direction.

5. An electrical vibrator unit comprising a base member having an annular groove, a vibrator unit having a base provided with a second annular groove, and a sleeve of resilient material interlocking at its ends with said grooves and providing spacing and connection means between said base member and said vibrator base.

6. An electrical vibrator unit comprising a base member having an annular groove, a vibrator unit having a base provided with a second annular groove, and a sleeve of resilient material interlocking at its ends with said grooves and providing a resilient connection between said base member and said vibrator base, said base member having a plurality of stepped spaced threaded peripheral surfaces substantially coaxial with said first named groove for receiving correspondingly threaded shield members for said unit.

7. An electrical vibrator unit comprising a base member having an annular groove, a vibrator unit having a base provided with asecond annular groove, and a sleeve of resilient material interlocking at its ends with said grooves and providing a resilient connection between said base menrber and said vibrator base, and said base member being provided with projecting plug-in terminal members.

8. A vibrator unit comprising in combination a base, a pedestal member extending substantially vertically from the base, elongated spring contact members extending along said pedestal, each being,r secured to said pedestal at one end adjacent to the base and having free contact bearing ends arranged in opposing relation tp each other on opposite sides of the pedestal member, said spring contact members being biased against said pedestal member, a vibratory armature means movable in contacting relation with and between saidl free ends of said members, said armature means including spring members secured to the pedestal adjacent to said base and extending therefrom substantially parallel with said spring contact members, and an electro-magnet supported from and located in spaced relation to said base in asociation with said armature means.

9. A vibratory circuit controlling device comprising incombination a base member, and a vibrator unit resiliently mounted thereon in spaced relation thereto, said unit including an armature mounted to vibrate in a plane` substantially at a right angle to and transverse of the base, and said unit having a mass and stillness such that its natural period of vibration is longer than the vibrational period of the armature, an electromagnet associated with said armature. operating contact means iorv controlling said electro-magnet including a spring contact member fixed at one end and having a free end in contacting relation to the armature, said member having a natural f period of vibration shorter than that of the armature whereby said member is stiiness controlled, and means including an adjustable stop screw arranged to contact with the free end of said contact member to open said contact means.

l0. A vibratory circuit controlling device comprising in combination a base member, and a vibrator unit resiliently mounted thereon in spaced relation thereto, said unit including an armature mounted to vibrate in a plane substantially at a right angle to and transverse of the base, a pair of nested spaced shield cans removably mounted mounted to vibrate in a plane substantially at a right angle to and transverse of the base, a pairv of nested spaced shield cans removably mounted yon said base' through the medium of screwthreaded connections therewith and providing with the base shielded enclosure means for the vibrator unit, means providing a well depending from said base member and communicating with the interior of said enclosure means, electric circuit controlling impedance elements mounted in said well, and means for sealing said well about said impedance elements.

12. A vibratory circuit controlling device comprlsing in combination a base member, and a vibrator unit resiliently mounted thereon in spaced relation thereto, said unit including an armature mounted to vibrate in a plane substantially at a right angle to and transverse of the base, a pair of nested spaced shield cans removably mounted on said base through the medium of screw-threaded connections therewith and providing with the base shielded enclosure means for the vibrator unit, said shield cans being of metallic material providing relatively thin walls, and means providing a sound absorbing lining on the interior oi' atleast one of said shield cans.

13. A vibrator device comprising a base member, la plurality of shield containers releasably mounted thereon in spaced relation to each other and a vibrator unit mounted on said base member for inclusion within said shield containers, said unittcomprising a base, a sleeve of resilient liliy material providing a ilegible connection between said base and base member, an amature mounted on said base for vibratory movement in a vertical plane transverse to the base and vibratory con- `tact means for controlling the operation of the armature having a period of vibration shorter than that of the armature and resiliently contacting therewith whereby said contact means is stiffness controlled.

14. A vibratory contact circuit controlling device comprising, in combination, a relatively heavy -base member having a series of threaded cylindrical surfaces thereon in stepped spaced relation to each other, a plurality of nested shield containers threaded .on said surfaces, a vibrator unit associated with said base member, a resilient connecting member having ilexible tapered walls between said base member and said unit and holding said unit in spaced relation to said base member, an armaturemember mounted for vibratory movement in a plane transverse of said base member and at substantially a right angle thereto,- an

actuating electro-magnet for said amature membery having spaced pole pieces for receiving saicll armature member between them. contacts for controlling the operation of said electro-magnet, and a ilx'ed spring contact member for one of said contactsarranged to contact with the armature,

said contact member having a natural frequency of vibration higher than that of the armature whereby it is stiffness controlled in connection with the armature.

15. A vibratory contact circuit controlling device comprising, in combination, a vibrator unit and an electrically shielded substantially sound-proof housing for said unit having a base member and a plurality of nested shield cans mounted thereon in spaced relation to each other, said vibrator unit comprising a base, an electro-magnet mounted in spaced relation to the base and having spaced pole pieces, means providing an armature body movable toward and between said pole pieces in close spaced relation thereto without striking the same, spaced supporting springs for the armature body, said springs extending at a right angle to the base, a spring contact member on each side of the armature extending substantially at a right angle to and from the base and having Afree ends disposed in spaced relation to the armature body, said spring contact members being bent in the direction of the armature for contact therewith, intermediate stop members for holding said springs in spaced relation to each other and a tapered sleeve of resilient material. providing a exible connection between said base member and said base whereby the latter is resiliently held in spaced relation to said base member.

16. In a vibratory contact circuit controlling device, a vibrator unit comprising an insulating base, a pedestal of insulating material mounted thereon, a bracket on said pedestal, an electro-magnet mounted on said bracket and having spaced pole pieces, an armature mass, spaced supporting springs for said armature mass comprising elongated strips of resilient material having curled edges adajcent to the armature mass and being secured to said pedestal and base, the

varmature mass being supported on the free ends thereof for movement between but out of contact with the pole pieces. a spring contact member mounted on said pedestal and having a free end disposed adjacent to and in contacting relation with the larmature lmass, said spring contact member being shorter than said supporting springs, a pair of elongated spring contact membersonoppositeaidesofthepedestallecuredto..

saidpedestalandbaseandextendingsubatantiallyparallel with saidspaceds rting springs with free ends on opposite sides and in opposing relation to the armature mass, means providing cooperating circuit controlling contacts between the armature and said spring contact members, and projecting stop means for said contactmemberscarriedbytheupperendof said pedestal.

l?. An electrical vibrator unit comprising a base. an electro-magnet supported from and lying in a piane substantially at aright angle to and intersecting said base, said electro-magnet havingapairofpolepiecesprovidingspaced parallel pole faces extending transversely of the base, a vibratory armature having a body movable between said pole faces but out of contact therewith, flexible spring mounting means for said amature secured to the base and having free ends carrying said armature body, a plurality of elongated spring contact members extending substantially parallel with said spring mounting means from the base and having free ends arranged in contacting relation to the armature on opposite sides thereof, one of said contact springs being relatively short and having a natural frequency of vibration higher than that of the armature, and said vibrator unit having a natural frequency of vibration lower than the period of vibration of the armature. and adjustable stop means for said last named one of said contact springs adapted to meet said contact spring adjacent to the free end thereof.

18. A vibratory circuit controlling device comprising in combination a base member, and a vibrator unit resiliently mounted thereon in spaced relation thereto, said unit including an armature mounted to vibrate in a plane substantially ata right angle to and transverse of the base, a pair of nested spaced shield cans removably mounted on said basethrough the medium of screw-threaded connections therewith and providing with the base shielded enclosure means for the vibrator unit, electro-magnet motor means for actuating said armature including a spring contact element mounted in contacting relation at one end with the armature, a resistor having common terminal connection with said spring contact member whereby it is included within the enclosure means, a plurality of spaced circuit controlling contact elements associated with the armature for controlling separate circuits, and a pair of circuit controlling impedance elements mounted in said base member within the connes of said enclosure means and electrically connected with the armature and two of said spaced circuit controlling contact members, whereby said circuit controlling impedance elements are included within the connues of said shielded enclosure means.

19. A circuit making and breaking device oomprising. in combination, an elongated casing. an electro-magnet mounted in one end of said casing and having pole faces located substantially y in a plane transverse of said casing. three spaced ao'oasu posed eccentric'ally with respect to said pole faces so that energization oi' the electro-magnet will produce movement of said armature and swins' said center contact into circuit closing engagement with one of the outer contacts, the other 4of said outer contacts being engageable by said center contact upon a return movement thereof when the electro-magnet is de-energized, said outer contacts being resiliently urged toward each other, and spacing ngers interposed between said outer contacts for abutment thereby to limit the inward movement thereof.

20. A circuit making and breaking device for a direct current transforming system comprising spaced contacts controlling separate circuits in said system, an intermediate and common contact for completing either circuit, means for reciprocating said common contact between said spaced contacts, all of said contactsbeing of resilient material and the spaced contacts being under a tension which urges said spaced contacts toward said common contact, and stop means underlying each of said spaced contacts for engagement therewith near the free ends thereof. l

21. A circuit making and breaking device for a direct current transforming system comprising spaced contacts controlling separate circuits in said system, an intermediate and common contact for completing either circuit, means for reciprocating said common contact between said spaced contacts, all of said contacts being of resilient material and the spaced contacts being under a tension which urgesl said spaced contacts toward said common contact, a limit iinger underlying each of said spaced contacts for engagement therewith, and means connecting said fingers and .maintaining a spaced relationship therebetween.

22. A circuit making and breaking device having the combination of three spaced contact elements formed of resilient material and supported at one end, intermediate members disposed between said elements, the outer elements being normally under a tension urging said elements into engagement with said members near the free ends thereof to deilne their proper adjustment relative to the center element, and means for reciprocating said center element into circuit closing contact alternately with said outer eiements.

23. In a circuit making and breaking device, the combination of three spaced contact elements formed of resilient material and supported at one end to extend in approximate parallelism in the same direction, intermediate members disposed between said elements, the outer elements being normally under a tension urging said elements into engagement with said members neat the free ends thereof, and an electro-magnet energia.- able to move said center element into contact with one of said outer elements and de-energizable to release said element for return movement into engagement with the opposite element.

24. In a circuit making and breaking device. the combination of three spaced contact elements formed of resilient material and supported by one end, intermediate members disposed between said elements, the outer elements being normally under a tension urging said elements into engagement with said members near the free ends thereof to denne their proper adjustment relative to the center element, and means for reciprocatingsaid center element into circuit closing contact alternately with said outer elements, said outer elements being free for movement against the tension thereof when engaged by said center element.

25. In a circuit making and breaking device, the

' combination of contact elements for alternately closing a plurality of circuits including spaced contacts and a movable resilient element, an electro-magnet, and an armature on said movable element disposed within the effective range of said electro-magnet, said armature in the normal position of said movable element being located eccentrically of said range for movement to establish one circuit immediately upon ener-v gization of said electro-magnet, said armature having a mass ample to carry said movable element in an opposite direction for completing another circuit upon de-energization of said electromagnet- 26. In a circuit controlling means the combination of abase, an electro-magnet mounted at one end of said base and having an active pole face located in a transverse plane relative to the base, a reed mounted on the other end of the base and' having a free end terminating adjacent to said pole face, an armature mounted on said free vend and supported by the reed for swinging movement in a plane substantially paralleling the plane of said face and closely adjacent there to, a pair of fixed contacts located one on either side of said reed, contact means on said reed engageable with either of said fixed contacts in the movement of said reed, said reed having a normally idle position at one side of the center of magnetic attraction of said active face. and

means for intermittently energizing vsaid electro- 

